Updates:
06.08.21
I finally found the time to dust off the source code and get her up and running again. This is mainly a bugfix release to (hopefully) eliminate the crashes caused by characters encoded by Fighter Factory Studio. So if VSelect has been refusing to start since you added new characters, try this new version. If you still find characters that cause problems (or any other bugs), please let me know.

I've also made the change requested by @K4thos to add basic compatibility with Ikemen Go. If the program can't find a data/mugen.cfg file it will look for save/config.json and load the motif from there instead. No support yet for any of Ikemen's extra features but I'd be interested to look at this in future. Until then I hope this is a useful update

11/10/2010:
New option: display hidden characters
Shift-dragging now swaps dropped character with target character
New menu option to open character def file
16/10/2010:
*Character list added
*New feature: drag/drop character file from Windows Explorer
15/11/2010:
*Added support for selecting/moving/inserting/replacing multiple characters
*Added order list
*New option to toggle drag/drop and shift-drag behaviour
23/11/2010:
*Added SFF2 support
06/12/2010:
*New option: keep a separate config for each copy of Mugen
*Added (provisional) SFF2.0.1 support\
*Added technical info to character properties dialog
10/01/2011:
*New option to display big portrait of selected character
06/03/2011:
*New feature: set maxmatches parameters via the Order list panel
*Size/position of the window are now saved between sessions
28/03/2011:
*Added stage list
25/08/2011:
*Added 'Included' column to chars list
12/06/2012
*New feature: lock cells to prevent their contents from being changed
*New option to allow RandomSelect cells to be used as free cells when the grid is full
18/06/2012
*Zoom option added
*Auto-backup option added (backs up before every save - on by default)

Hello friends!
Hopefully some of you will find this useful.  It's a new tool I've been working on to enable editing of your Mugen select screen using a visual drag&drop interface.

I've had a stab at rendering the select screen as accurately as I could, though it's not perfect; in particular the alpha blending is only an approximation of how it looks in Mugen.  I think it's close enough, in general.

To give an idea of how to use it, I've made a short video.  Hopefully this demonstrates the basic idea:


It should work with WinMugen, hi-res WinMugen and Mugen 1.0.  The program reads from mugen.cfg and the system.def file of the selected motif, and tries to scale the screen accordingly; it should get it right for Mugen 1.0 but for hi-res WinMugen you need to use the setting available via the File -> Options menu.

Other options allow you to hide the top layer while dragging a character around - useful for some motifs where the grid is partially hidden.  You can also choose to show or hide empty cells (note this only applies to the viewing mode within the tool; the actual Mugen setting is not affected).  Also you can choose to disable alpha-blending (I added this because for screens that make heavy use of these effects the program can start to lag if it tries to display them all; this particularly applies if a transparent animation is used as the cell background).

Animations are not played, but the program will try to display single frames where possible.  It tries to be clever and exclude any frames that might obscure the screen, but I included an option to randomize the frames in case one of these does get displayed.  There's also the option to exclude animation elements completely.

What else... zipped characters are supported (although the program may be slow to load if a lot of these are included).  Characters can be added from anywhere; if they're not located in the chars directory then an absolute path will be used (however zipped characters will be copied to the chars directory as this seems to be a Mugen requirement).

Cons:  the more characters in the select screen, the longer the program will take to load.  Flashier motifs with lots of alpha-blending can also slow things down, as mentioned.  Other than that, no doubt there will be some select screen parameters I've failed to implement correctly, so please feel free to post details of any errors you come across.  Also any random crashes, weird behavior, etc.  Note: one issue I'm aware of is the width parameter, used with parallax elements for a perspective-type effect.  I don't support this currently and just display the sprites as they are.

One more thing to be aware of: a backup is made of every file before it's first edited by the program - named (for example) "select.def.vselect.bak".  The select screen def file is the only one ever edited, unless you use the "set as default motif" option which just updates the appropriate line in mugen.cfg.